In a medium bowl, stir together flour, brown sugar, cinnamon and 1 teaspoon salt. Add diced butter and rub in with your fingers until small to medium clumps form. Mix in pecans. Cover and place into the refrigerator until needed.

To prepare streusel center

In a small bowl, stir together brown sugar, cinnamon, salt and pecans.

In a large mixing bowl, beat together butter and sugar until light and fluffy. Mix in eggs, one at a time, beating until well combined after each. Mix in vanilla. Mix in flour mixture in 3 additions, alternating with sour cream, beginning and ending with the dry ingredients. Beat batter just until combined.

Spoon half the batter into a 9" tube pan (with a removable bottom) coated with nonstick spray with flour added. Scatter the streusel center mixture evenly over batter. Dollop remaining batter mixture over the top, spreading smooth with an offset spatula. Scatter streusel topping mixture evenly over the top of batter.

Place pan into the oven and bake until golden brown and a wooden skewer placed into the center of the cake comes out mostly clean with a few moist crumbs attached, about 50 to 60 minutes. Remove pan from the oven and place onto a wire rack to cool. Unmold cake and place on a serving platter.

To prepare the glaze

In a small bowl, stir together confectioners' sugar and milk. Drizzle glaze all over the top of the cake.